You can put as many thousand quid's worth of stuff inside it as you like. It's not gonna change the basic challenges which you won't be able to get around.
Challenge 1: Space. A ski season in the alps probably requires more kit than any other choice of trip. Where are you gonna store it all?
Challenge 2: Expense. Presumably the point of going in the van is to chase snow all over the alps. This means you'll be buying day passes mostly (i.e. you won't have a season pass). Even if you only ski half the days of the season, this is gonna work out as several thousand euros worth of lift tickets. Hope you've got a trust fund.
Challenge 3: Drying. Your stuff has to be in the van at all times. This ain't the beach, you can't hang your stuff up to dry on a palm tree. I don't even wanna think about what your van is gonna smell like with 2+dudes' stuff semi permanently wet inside it.
Challenge 4: Your van breaks down- what you gonna do- that's your house. In many cases in the alps, the nearest garage might be fucking miles away. What happens if you need to leave the van at the garage for a couple of days? You gonna live in the garage?
Challenge 5-55. Fuck knows. Millions.
Buy a van, at least spend a summer in it. Summer's a lot more forgiving and you'll be able to figure out how to optimise van living so that by the time you get to the winter you will have most of the challenges figured out.
But mostly, forget trying to spend 6 months living in a van anywhere with more than 1 other person.